It's more than that though. Apple attracts more customers that are more willing to spend money on their platform. In doing so, they attract more high quality applications and developers that can make a living off of that ecosystem. Android is doing that as well, but more slowly, in no small part due to the difficulty people often face with the Android Marketplace.
How do you define high end? Because to me, and people in general out there, Apple is (always) high end in the sense that they're about as high quality as you can get as far as these kind of devices go. They don't charge "high-end" prices for some of their devices, but price isn't the metric you judge something to be high end or not.
Of course, if high end for you means diamond studded or gold plated, then we have a different case here.
If anything, it's two competing bazaars. Apple's just been able to attract more artists to sell in theirs.